AIMS Our aim was to evaluate the safety and efficacy of intracoronary (IC) nicorandil as an alternative choice of hyperaemic agent for invasive physiologic studies.

METHODS AND RESULTS A total of 480 intermediate coronary lesions from 429 patients enrolled from six Japanese and Korean centres were analysed. IC nicorandil showed earlier achievement of hyperaemia (time to the lowest FFR: 18.0 s [1st and 3rd quartile value 15.6-21.5] vs. 44.0 s [36.0-60.0], p<0.001) with similar hyperaemic efficacy, compared with intravenous (IV) adenosine/ATP (FFR 0.82 [0.75-0.87] vs. 0.82 [0.74-0.88], p=0.207). FFR measurements with both agents showed excellent correlation and classification agreement (CA) for FFR ≤0.80 (r=0.941, ICC 0.980, CA 90.8%, kappa=0.814, AUC of nicorandil 0.980, all p<0.001). Only three patients (0.7%) showed changes in classification across the grey zone (0.75-0.80). IC nicorandil produced fewer changes in blood pressure (BP) and heart rate (HR) and showed less chest pain than IV adenosine/ATP (all p<0.001). When comparing ΔFFR according to ΔBP or ΔHR between IV adenosine/ATP and IC nicorandil, there were no correlations, either between ΔFFR and ΔBP (r=-0.114, p=0.091), or between ΔFFR and ΔHR (r=1.000, p=0.151).

CONCLUSIONS Nicorandil IC bolus injection is a simple, safe and effective hyperaemic method for FFR measurement and can be used as a substitute for adenosine.